Picking the exact time of the trend reversal (or taco transition ;) is a little difficult here..
The price on Mt.Gox was behaving unnaturally in it's last weeks as we all know. When FIAT withdrawals weren't going through the price was way above other exchanges and when BTC withdrawals were halted price went in the opposite direction, also way below the price of ...

just an idea
Notice how the last two run ups both started shortly after crossing the big red dashed line in the trend channel.
But remember you can't foresee the future by looking at the past, so take this into consideration ;)